April 5, 2026: LEMON Manuals is launched! Read the announcement.

Engine Control Module: Testing and Inspection

CHECK AT THE ENGINE CONTROL MODULE (ECM) OR THE POWERTRAIN CONTROL MODULE (PCM)

1. Disconnect the ECM or the PCM connectors B-19, B-20, B-21, B-22 and B-23, and connect check harness special tool MB991923 between the ECM connectors or the PCM connectors.
2. Measure the voltage between each check harness connector terminal and check harness connector ground terminal (No. 25 or No. 29).

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 1:

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 2:

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 3:

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 4:

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 5:

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 6:

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 7:

Check Harness Special Tool MB991923 Connector Terminal Arrangement Part 8:

TERMINAL VOLTAGE CHECK CHART

ECM <M/T> Or PCM <A/T> Harness Side Connector Terminal Arrangement Part 1:

ECM <M/T> Or PCM <A/T> Harness Side Connector Terminal Arrangement Part 2:

TERMINAL RESISTANCE AND CONTINUITY CHECK